Photodynamic Modification of Native HCN Channels Expressed in Thalamocortical Neurons.,ACS Chemical Neuroscience

当前位置： X-MOL 学术 › ACS Chem. Neurosci. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Photodynamic Modification of Native HCN Channels Expressed in Thalamocortical Neurons.
ACS Chemical Neuroscience ( IF 4.1 ) Pub Date : 2020-03-06 , DOI: 10.1021/acschemneuro.9b00475
Fusheng Wei _{1,

2} , Qiang Wang ₁ , Jizhong Han ₁ , Priyodarshan Goswamee ₁ , Ankush Gupta ₁ , Adam Rory McQuiston ₁ , Qinglian Liu ₁ , Lei Zhou ₁

Affiliation

The photodynamic process requires three elements: light, oxygen, and photosensitizer, and involves the formation of singlet oxygen, the molecular oxygen in excited electronic states. Previously, we reported that heterologously expressed hyperpolarization-activated cAMP-gated (HCN) channels in excised membrane patches are sensitive to photodynamic modification (PDM). Here we extend this study to native HCN channels expressed in thalamocortical (TC) neurons in the ventrobasal (VB) complex of the thalamus and dopaminergic neurons (DA) of the ventral tegmental area (VTA). To do this, we introduced the photosensitizer FITC-cAMP into TCs or DAs of rodent brain slices via a whole-cell patch-clamp recording pipette. After illumination with blue light pulses, we observed an increase in the voltage-insensitive, instantaneous Iinst component, accompanied by a long-lasting decrease in the hyperpolarization-dependent Ih component. Both Ih and the increased Iinst after PDM could be blocked by the HCN blockers Cs+ and ZD7288. When FITC and cAMP were dissociated and loaded into neurons as two separate chemicals, light application did not result in any long-lasting changes of the HCN currents. In contrast, light pulses applied to HCN2-/- neurons loaded with FITC-cAMP generated a much greater reduction in the Iinst component compared to that of WT neurons. Next, we investigated the impact of the long-lasting increases in Iinst after PDM on the cellular physiology of VB neurons. Consistent with an upregulation of HCN channel function, PDM elicited a depolarization of the resting membrane potential (RMP). Importantly, Trolox-C, an effective quencher for singlet oxygen, could block the PDM-dependent increase in Iinst and depolarization of the RMP. We propose that PDM of native HCN channels under physiological conditions may provide a photodynamic approach to alleviate HCN channelopathy in certain pathological conditions.

中文翻译：

丘脑皮质神经元中表达的天然 HCN 通道的光动力学修饰。

光动力过程需要三个元素：光、氧和光敏剂，并涉及单线态氧（处于激发电子态的分子氧）的形成。以前，我们报道了离体膜片中异源表达的超极化激活 cAMP 门控 (HCN) 通道对光动力修饰 (PDM) 敏感。在这里，我们将这项研究扩展到在丘脑的腹基底 (VB) 复合体和腹侧被盖区 (VTA) 的多巴胺能神经元 (DA) 中的丘脑皮质 (TC) 神经元中表达的天然 HCN 通道。为此，我们通过全细胞膜片钳记录移液器将光敏剂 FITC-cAMP 引入啮齿动物脑切片的 TC 或 DA。在用蓝光脉冲照射后，我们观察到电压不敏感的瞬时 Iinst 分量增加，伴随着超极化依赖性 Ih 分量的长期下降。Ih 和 PDM 后增加的 Iinst 均可被 HCN 阻断剂 Cs+ 和 ZD7288 阻断。当 FITC 和 cAMP 被分离并作为两种单独的化学物质加载到神经元中时，光照不会导致 HCN 电流的任何持久变化。相比之下，与 WT 神经元相比，应用于装载有 FITC-cAMP 的 HCN2-/- 神经元的光脉冲使 Iinst 成分减少了更多。接下来，我们研究了 PDM 后 Iinst 的长期增加对 VB 神经元细胞生理学的影响。与 HCN 通道功能的上调一致，PDM 引起静息膜电位 (RMP) 的去极化。重要的是，Trolox-C，一种有效的单线态氧猝灭剂，可以阻止 Iinst 的 PDM 依赖性增加和 RMP 的去极化。我们提出生理条件下天然 HCN 通道的 PDM 可以提供一种光动力学方法来减轻某些病理条件下的 HCN 通道病。

更新日期：2020-03-06

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11